Tuesday, October 1, 2019

Climate Change: Measuring Carbon

One aspect of climate change science is understanding how to measure the global carbon cycle. The Deep Carbon Observatory (DCO) is a global group of more than 1,000 scientists who study carbon cycling from the Earth’s core to the edge of space. Live Science discusses an article on current understanding. DCO data suggests that with some exceptions, carbon release into the atmosphere has been about the same as carbon sinking into the planet's interior at tectonic plate boundaries for the last 500 million years. CDO believes the balance results in breathable air and a land and sea climate that supports biodiversity.

Global carbon cycle -- carbon dioxide in gigatons
(Source: Figure 7.3, IPCC AR4)

CDO data shows the current rate of human caused carbon flow is about 80-fold higher than release of carbon by present-day volcanoes. Over time, various events or ‘perturbations’ have thrown the cycle out of balance, causing increases in greenhouse gas carbon dioxide (CO2) and global climate disruption over hundreds of years. The perturbations are often resulting in widespread extinctions.

Since 1750, CDO estimates that human activity has released about 2,000 gigatons of CO2 into the air. The Chicxulub asteroid impact that is believed to have caused dinosaur mass extinction 65 million years ago is believed to have released about 1,400 gigatons of CO2. The CO2 release eventually led to global warming. A separate study from 2018 that analyzed fossil records suggests that the Earth's temperature increased by 5 degrees Celsius (9 degrees Fahrenheit) for thousands of years.

The Chicxulub asteroid (~6-9 mile diameter) interacting 
with Earth and its life forms

Live Science writes that DCO researchers believe the “pace and scale at which humans are disturbing the planet's carbon balance are comparable to some of the most cataclysmic geologic events in history. It's likely, the researchers wrote, that the results of this era of man-made meddling could look similar to the troubled centuries following Chicxulub and other ancient cataclysms. This era, the researchers concluded, ‘is likely to leave its legacy as a mass extinction from greenhouse-induced climate change on a biosphere already at a tipping point caused by habitat loss.’ ”

Given the apparent wealth and political power of climate science deniers in the US to block action climate change legislation, it looks like other countries are going to have to try to deal with global warming without us. Public opinion is shifting toward increasing concern, but that has been mostly irrelevant so far.


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